1. Field of the Invention
The present invention relates to a treatment device.
2. Description of the Related Art
Generally, treatment devices for treating biotissues by using high-frequency energy and thermal energy are known. For example, Jpn. Pat. Appln. KOKAI Pub. No. 2009-247893 discloses the following treatment device. Specifically, the treatment device includes an openable/closable holder for holding a biotissue to be treated. A part of the holder contacting the biotissue is provided with a high-frequency electrode to apply a high-frequency voltage and a heat-generating chip to heat the high-frequency electrode. In addition, the holder is provided with a cutter. When such a treatment device is used, first, the biotissue is held with the holder, and a high-frequency voltage is applied to the biotissue. Then, the biotissue is heated by the holder, and thereby the biotissue is anastomosed. It is also possible to perform excision by a cutter attached to the holder, in a state where the biotissue end portion is inosculated.
To perform stable biotissue anastomosis in a treatment device as disclosed in Jpn. Pat. Appln. KOKAI Pub. No. 2009-247893, it is necessary to control a temperature of a heat-transfer member contacting the biotissue, such as the electrode of the above holder, with high accuracy. In addition, it is required to increase the temperature of the heat-transfer member to a desired temperature in a short time from the start of heating. To increase the temperature of the heat-transfer member with a small heat-generating chip in a short time, it is necessary to supply much electric power to the heat-generating chip at an early stage of heating. As a result, the heat flux density from the heat-generating chip to the heat-transfer member becomes very large, and a difference in temperature between the heat-generating chip and the heat-transfer member increases.
For example, when the heat-transfer member is provided with a temperature sensor and the electric power supplied to the heat-generating chip is controlled based on the temperature of the heat-transfer member measured by the temperature sensor, the temperatures of the heat-generating chip and surrounding members may be increased to a temperature enough to break them, due to the difference in temperature between the heat-generating chip and the heat-transfer member. It is also possible to obtain the temperature of the heat-generating member without using the temperature sensor on the heat-transfer member. For example, it is possible to obtain the temperature of the heat-generating member, based on a change in a resistance of the heat-generating member of the heat-generating chip. The heat-generating chip or the like can be prevented from being broken by controlling the temperature of the heat-transfer member based on the temperature obtained as described above. To achieve this structure, however, it is necessary to reduce the individual variation in the resistance of the heat-generating member, and to obtain a relation between the temperature and the resistance in advance with high accuracy, to obtain the temperature of the heat-generating chip with high accuracy. This increases the cost of the whole system.